JP4507944B2 - Earth leakage breaker - Google Patents

Description

  The present invention relates to an earth leakage circuit breaker that is used for an electric light distribution board and the like, in particular, to detect an earth leakage using a zero-phase current transformer, and more specifically, a voltage electrode and a neutral electrode are housed in one housing to detect an earth leakage. The present invention relates to an improvement in an assembling method of a two-pole one-element type earth leakage breaker configured to store a portion in the other casing.

Earth leakage breaker in the international standard as an example (IEC), those with a built-in overcurrent elements (r esidual c urrent operated circuit- b reakers with integral o vercurrent protection, abbreviated RCBOs) and having no overcurrent elements (r esidual c urrent operated c ircuit- b reakers without integral overcurrent protection, can be roughly divided into abbreviated RCCBs), when the RCBOs, similar to the circuit breaker, that it comprises an overcurrent trip element is, of course, Needless to say, it is also required to cut off a large current such as a short-circuit current to prevent burning of the electric circuit.

  With regard to the interruption of this large current, an electromagnetic repulsive force is applied to the arc extinguishing chamber provided in the earth leakage breaker separately from the so-called normal current path, particularly via the overcurrent tripping element. It is widely known that the arc is cut in the arc extinguishing chamber while being guided while being used and a current path by the arc is secured. This interruption method is generally called an arc traveling method.

  By the way, the two-pole earth leakage breaker is often arranged on the wiring from the voltage pole to the load and back from the load to the neutral pole in the distribution path. The element may be provided at least on the voltage electrode side. Such a leakage breaker is usually called a two-pole one-element type. Even in this two-pole one-element type, the members related to the arc traveling method described above are provided not only on the voltage pole side but also on the neutral pole side (see, for example, Patent Document 1).

JP 2002-184294 A (FIGS. 1, 2 and 4)

  In the conventional earth leakage breaker, the voltage electrode and the neutral electrode are housed in one housing, and the earth leakage detection part is housed in the other housing, and the neutral electrode also requires a member related to the arc traveling method. In particular, the neutral pole electric circuit has to be configured by a plurality of members, and the cost is increased due to the complexity of assembly.

  The present invention has been made to solve the above-described problems. The voltage electrode and the neutral electrode are housed in one housing, and the leakage detection portion is housed in the other housing. Also, the purpose of the present invention is to obtain an earth leakage circuit breaker that can be easily assembled without changing the component arrangement configuration such as arranging members relating to the arc traveling system.

In the earth leakage breaker according to the present invention, the cover, the middle base, and the insulating casing including the base, the handle having a handle portion that can be opened and closed from the outside, and the stationary contact mounted inside the insulating casing. A stator, a movable contact contacting and separating from the stator, an opening / closing mechanism that drives the movable contact, an electromagnet device that operates the opening / closing mechanism in response to an overcurrent, and a main circuit Generated when the movable contactor is driven, a zero-phase current transformer that detects the leakage current of the coil, a tripping coil that operates the switching mechanism in response to a signal detected by the zero-phase current transformer An earth leakage circuit breaker having an arc extinguishing chamber for cutting an arc to be connected, a load conductor mounted in the inside of the insulating casing, and the movable contact connected by a flexible electric wire to which a conductive pipe is fixed , and the conductive pipe above vanishing It is obtained by configured to be disposed in the vicinity of the chamber.

  As described above, the present invention can provide a simple and inexpensive two-pole one-element type earth leakage breaker while having a high breaking performance.

Embodiment 1 FIG.
1 is an external perspective view showing an open state (hereinafter abbreviated as “OFF”) of an earth leakage circuit breaker according to Embodiment 1 of the present invention, and FIG. FIG. 3 is a side view when the base is removed from FIG. For convenience, FIG. 2 is referred to as a voltage electrode side view, and FIG. 3 is referred to as a neutral electrode side view.

  FIG. 4 is an enlarged view centered on the arc extinguishing chamber of the neutral electrode in the closed state (hereinafter abbreviated as ON), and FIG. Is shown. Further, in FIG. 5, a part of the flexible wire and the pipe are shown in a cross-sectional shape for easy understanding of the current path. In addition, FIG. 6 is a side view seen from the A direction with the cover removed in FIG.

  In FIG. 1, a cover 1, a ground leakage middle base 2, a middle base 3, and a base 4 constitute a casing of a ground fault circuit breaker 101 and are each formed of a synthetic resin. An opening / closing mechanism section, which will be described later, is housed in the middle base 3, and a handle 5 interlocking with the opening / closing mechanism section projects from the handle window hole 3 a of the middle base 3 to the surface of the middle base 3, It is well known that it can be operated. It is also well known that the handle 5 indicates the OFF state because the front side is the power supply side terminal fastening hole 6 and the depth side is the load side terminal fastening hole 7 on the paper surface.

  The earth leakage base 2 accommodates a later-described trip coil and zero-phase current transformer necessary for the earth leakage operation, and an earth leakage display piece (not shown) linked to the trip coil is located at the position of the earth leakage display window 2a. As is well known, it is known to the outside that the earth leakage breaker 101 has made an earth leakage interruption by moving to. Reference numeral 8 denotes a leakage test button. However, the leakage display window 2a and the leakage test button 8 do not form a main part of the present invention, and a detailed description thereof will be omitted. In the first embodiment, the fastening holes 6a and 7a arranged on the same line are connected to the electric circuit corresponding to the voltage electrode, and the electric circuits corresponding to the neutral electrode are connected to 6b and 7b, respectively. Will be. Hereinafter, the current path from the power supply side to the load side will be described in detail for each pole.

  First, the voltage electrode will be described with reference to FIG. For example, a power supply side electric wire (not shown) is inserted into the power supply side terminal 9 and connected to the stator 11 through the power supply side terminal tightening hole 6a with the tightening screw 10. The stator 11 is provided with a fixed contact 12, which is in an ON state, that is, when the handle 5 is rotated counterclockwise on the paper surface, it comes into contact with the movable contact 13 that is interlocked with the opening / closing mechanism 102. It will be. Therefore, the current flows in the order of the stator 11, the fixed contact 12, and the movable contact 13, and then flows through the flexible wire 14 and the coil 15 constituting the electromagnet device 103 that operates when a short circuit occurs.

  As shown in FIG. 6, the end 15a of the coil 15 protrudes from the inner wall 2b of the middle base 2 for electric leakage, and a through conductor 17 passing through the zero-phase current transformer 16 is fixed to the end 15a. As shown in FIG. 2 again, the through conductor 17 is fixed to the bimetal 18 constituting the overcurrent tripping device 104. The through conductor 17 is inserted into the load conductor 19 and the load side terminal 20 and tightened to the load side terminal. For example, a load-side electric wire (not shown) connected to the load conductor 19 by the fastening screw 10 flows from the hole 7a.

  Next, the neutral electrode will be described with reference to FIG. For example, a power supply side electric wire (not shown) is inserted into the power supply side terminal 21 and connected to the stator 22 by the tightening screw 10 from the power supply side terminal tightening hole 6b. The stator 22 is provided with a stationary contact 23. The movable contactor is interlocked with the opening / closing mechanism unit 102 in the ON state, that is, by rotating the handle 5 clockwise on the paper surface, similarly to the voltage electrode. 24 will come into contact. Since the flexible wire 25 is fixed to the movable contact 24, the current flows in the order of the stator 22, the fixed contact 23, the movable contact 24, and the flexible wire 25.

  As can be seen from FIG. 2, the flexible wire 25 crosses the voltage electrode side, and as shown in FIG. 6, it can also be seen that it also serves as a penetrating conductor that penetrates the zero-phase current transformer 16. The flexible electric wire 25 is fixed to a load conductor 26 protruding from the inner wall 2b of the middle base 2 for electric leakage. Hereinafter, the load conductor 26 is inserted into the load side terminal 27 again as shown in FIG. For example, a load side electric wire (not shown) connected to the load conductor 26 by the tightening screw 10 flows from the load side terminal tightening hole 7b.

  When an overcurrent occurs in the above-described ON state, the bimetal 18 shown in FIG. 2 rotates clockwise on the paper surface with the fixing point with the load conductor 19 as a fulcrum, so that the trip cam 28 also rotates clockwise. The protrusion 28a of the trip cam 28 releases the engagement between the latch 29 and the U pin 30. Then, the holding force of the movable contact 13 (the neutral pole is the movable contact 24) obtained by the latch 29 with respect to the fixed contact 12 (the neutral pole is the fixed contact 23) is released, and FIG. As shown in 3), it is well known that the switch is turned off. Note that a series of operations of the opening / closing mechanism 102 centering on the latch 29 does not form a main part of the present invention, and thus detailed description thereof is omitted.

  Next, when a short circuit occurs in the ON state, the plunger 31 moves to the right on the paper surface of FIG. 2 due to the magnetic flux generated by the coil 15, and the latch 29 and the U pin 30 are engaged as in the case of the overcurrent occurrence described above. The combination is released and the movable contact 13 (the neutral pole is the movable contact 24) is separated from the fixed contact 12 (the neutral pole is the fixed contact 23). The series of operations of the opening / closing mechanism 102 at this time does not form a main part of the present invention, and detailed description thereof is omitted. However, the fixed contact 12 (the neutral electrode is the fixed contact 23) and the movable contactor are omitted. The disappearance of the arc generated by the arc traveling system 13 (neutral pole is the movable contact 24) is an essential part of the present invention and will be described in detail below.

  First, with respect to the voltage electrode, the arc generated between the fixed contact 12 and the movable contact 13 is moved between the stator 11 and the arc runner 32. At this time, the current direction to the tip 11a of the stator 11 is 2, which constitutes the arc extinguishing chamber 33, the repulsive force of the magnetic field generated when the direction of the current from the lower end grid 33a to the upper end grid 33b is different, and the lower end The arc is extinguished by the repulsive force of the magnetic field generated when the direction of the current from the grid 33a to the grid 33b at the upper end and the direction of the current to the U-turn part 32a of the arc runner 32 are different directions. Led to.

  Therefore, as described above, the normal current path is the stator 11, the fixed contact 12, the movable contact 13, the flexible electric wire 14, the coil 15, the penetrating conductor 17, the bimetal 18, and the load conductor 19. Since the arc between the stator 11 and the arc runner 32 and the arc runner 32 are fixed to the load conductor 19 as can be seen from FIG. 2 only at the time of occurrence, the stator 11 → the arc runner 32 → the load conductor. It turns out that it bypasses with 19. However, since the other grids (not numbered) including the grid 33a at the lower end and the grid 33b at the upper end are magnetic plates having V-shaped notches, the arc is cut in the arc extinguishing chamber 33 and short-circuited. As is well known, a large current accompanying the generation is quickly cut off. The arc runner 32 is preferably made of iron in order to obtain the repulsive force of the magnetic field described above.

  On the other hand, as shown by the arrows shown in FIG. 4, the neutral pole normally flows in the order of the stator 22 → the fixed contact 23 → the movable contact 24 → the flexible electric wire 25, but the flexible electric wire 25 is connected to the arc extinguishing chamber 34. Therefore, when the short circuit occurs, it is understood that the stator 22 and the flexible electric wire 25 are bypassed as shown by the arrow in FIG. Therefore, as described above, the flexible electric wire 25 also serves as a through conductor penetrating the zero-phase current transformer 16, which leads to a reduction in the number of parts, and thus an assembly cost can be reduced.

  The process leading to the extinction of the arc, that is, the interruption is almost the same as that of the voltage electrode. More specifically, as shown in FIG. 5, the direction of the current to the tip 22a of the stator 22 and the arc extinguishing chamber 34 are configured. The repulsive force of the magnetic field generated when the direction of the current from the lower end grid 34a to the upper end grid 34b is different, and the lower end grid 34a to the upper end grid 34b. The direction of the current and the direction of the current to the fixing point 35a with the flexible wire 25 of the conductive pipe 35 having the function of the arc runner 32 described in the voltage electrode are different directions. The arc is guided to the arc extinguishing chamber 34 by the repulsive force. Here, the fixing point 35a has a function corresponding to the U-turn part 32a for obtaining a current toward the fixing point 35a, that is, in terms of a voltage pole. The current continues toward the load conductor 26 (see FIG. 3). Therefore, the fixing point 35a needs to be firmly electrically connected by caulking or the like.

  Further, like the arc runner 32, the conductive pipe 35 is preferably iron in order to obtain the above-described repulsive force of the magnetic field. Therefore, for this neutral pole that does not require an electromagnet device or an overcurrent tripping device, a flexible electric wire composed of, for example, a copper wire without using an arc runner such as iron, as shown in Patent Document 1, is used. 25 is incorporated into the current path not only when a short circuit occurs but also during normal times, so heat generation due to energization can be suppressed, and a ripple effect such as a degree of freedom in design and an upgrade of the rated current can be expected.

  As can be seen from FIG. 6, the present invention detects the leakage current of the electric circuit by passing the through conductor 17 (voltage electrode) and the flexible electric wire 25 (neutral electrode) through the zero-phase current transformer 16. In response to the detected signal, the trip mechanism 102 is actuated by the tripping coil 36, and the leakage breaker 101 that cuts off the electric circuit is reduced in the number of parts required for the current path while having high breaking performance. However, when attention is paid to the suppression of heat generation due to energization as described above, the flexible wire 25 is not passed through the zero-phase current transformer 16 and is fixed to the load conductor 26 as it is, that is, the leakage current is removed. Needless to say, the effect can be expected even with a circuit breaker having no function.

It is an external appearance perspective view which shows the open state of the earth leakage circuit breaker in Embodiment 1 of this invention. It is the side view which removed the cover and the middle base for electric leakage in FIG. It is the side view which removed the base in FIG. 1 and was seen from the B direction. It is an enlarged view centering on the arc-extinguishing chamber of a neutral pole in the closed state of the earth leakage circuit breaker in Embodiment 1 of this invention. It is an enlarged view centering on the arc-extinguishing chamber of a neutral pole at the time of short circuit occurrence of the earth-leakage circuit breaker in Embodiment 1 of this invention. It is the side view which removed the cover in FIG. 1 and was seen from the A direction.

Explanation of symbols

1 Cover, 2 Medium base for earth leakage, 3 Medium base, 4 Base, 5 Handle,
11 Stator, 12 Fixed contact, 13 Movable contact, 16 Zero-phase current transformer,
22 Stator, 23 Fixed contact, 24 Movable contact, 25 Flexible wire,
26 load conductor, 33, 34 arc extinguishing chamber, 35 conductive pipe, 35a fixing point,
36 trip coil, 101 earth leakage circuit breaker, 102 switching mechanism,
103 Electromagnet device.

Claims (3)

An insulating casing comprising a cover, a middle base, and a base; a handle having a handle portion that can be opened and closed from the outside; a stator mounted inside the insulating casing and having a fixed contact; and facing the stator. Movable contactor, an open / close mechanism that drives the movable contact, an electromagnet device that operates the open / close mechanism in response to overcurrent, and a zero-phase current detection that detects a leakage current of the main circuit A tripping coil that operates the open / close mechanism in response to a signal detected by the zero-phase current transformer, and an arc extinguishing chamber that cuts off an arc generated when the movable contactor is driven. In the earth leakage breaker provided,
The load conductor mounted inside the insulating casing and the movable contact are connected by a flexible electric wire having a conductive pipe fixed thereto, and the conductive pipe is disposed in the vicinity of the arc extinguishing chamber. An earth leakage circuit breaker characterized by being configured as described above. The earth leakage circuit breaker according to claim 1 , wherein the material of the conductive pipe is iron. The leakage point according to claim 1 or 2 , wherein the fixing position of the conductive pipe and the flexible electric wire is the tip of the conductive pipe on the side close to the fixing position of the flexible electric wire and the movable contact. Circuit breaker.

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